There are a number of mechanisms by which window in buildings are opened and/or closed.
These mechanisms include:                Direct operation of a handle to unlock the window and then manual operation of the handle to open/close the window sash or by exerting manual force to the window sash;        A gearbox with a manually operated handle remotely connected to the window sash via links, rods or cables. Operation of the gearbox handle controls the opening/closing of the window sash;        An electric motor/gearbox is directly or remotely attached to the sash and the opening/closing of the window sash is controlled by activating or deactivating the motor either directly or indirectly.        
These systems require energy only when the window is being opened or closed. Therefore, they involve a relatively large amount of energy, but generally only for the short period of time in which the movement of the window takes place. These systems and devices are therefore “sized” in accordance with the high energy requirements in mind.
The inventors of the present invention have found that utilisation of a low power multiple cycle means to “charge” an accumulator, the size of the system used to open/close the window can be reduced while maintaining the availability of the large amounts of energy needed to open/close the window.
Further, when moving the louvres in a louvre window from a point where the louvres are fully open to the point where the louvres are fully closed, the maximum load that needs to be overcome by a drive mechanism and therefore the maximum force that needs to be applied is that over the final 10° of the closing cycle (and the first 10° of the opening cycle).
Presently louvres are operated manually via a handle which is connected to the louvre operating mechanism or remotely via rods/links to a remote manual or pneumatic or electric device as a power source.
Some issues associated with the conventional mechanisms used to accomplish the movement are:                The basic mechanics of the remote mechanisms are such that they become less efficient as the louvre approaches the locking/final closed position, that is, the position where the maximum force is required. As a result, the device is deliberately engineered according to the maximum force required to be overcome and the apparatus used is consequently large or oversized (when compared to an apparatus that is only designed to operate the louvres through the rest of the cycle). The size of the apparatus means that it cannot be housed within the window frame, and all rods or other linkages are located outside the window frame.        The rods/links and power source are all outside the frame as well due to their size and must be installed separately after the louvre window has been installed, making the device unsightly.        The energy required to drive the system is (relatively) very high because of the inbuilt inefficiency at the point of highest load.        The cost of the remote control system (whether manual or electric) is high (both in component cost and installation cost) because of the size of the equipment required to overcome the high load point.        The system is aesthetically undesirable due to the exposure of the drive system and rods/links.        
It would therefore be a significant advance over the conventional mechanisms if a drive mechanism is provided such that its mechanical advantage is at its greatest at the point where the drive mechanism has to overcome the highest load and that the mechanisms mechanical advantage is at its least when the resistance is least.
It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.